Quantifying the Mass Balance of Ice Caps on Severnaya Zemlya, Russian High Arctic. I: Climate and Mass Balance of the Vavilov Ice Cap

Abstract

Due to their remote location within the Russian High Arctic, little is known about the mass balance of ice caps on Severnaya Zemlya now and in the past. Such information is critical, however, to building a global picture of the cryospheric response to climate change. This paper provides a numerical analysis of the climate and mass balance of the Vavilov Ice Cap on October Revolution Island. Mass balance model results are compared with available glaciological and climatological data. A reference climate was constructed at the location of Vavilov Station, representing average conditions for the periods 1974–1981 and 1985–1988. The site of the station has a mean annual temperature of -16.5ºC, and an annual precipitation of 423 mm water equivalent. The mass balance model was calibrated to the measured mass balance, and tested against the time-dependent evolution of the englacial temperatures (to a depth of 15 m). The mass balance model was then converted to a distributed model for the entire Vavilov Ice Cap. Model results predict the spatial distribution of mass balance components over the ice cap. Processes involving refreezing of water are found to be critical to the ice cap’s state of health. Superimposed ice makes up 40% of the total net accumulation, with the remaining 60% coming from firn that has been heavily densified by refreezing.